Feature Request: Sidebar Groups

the Feature Request Site is inactive. How about a bit of inspiration from others:

The sidebar in any Finder was always a mess. People hack it (with sidebar separators) to make it more organized and useful, but it's really limited.

Others have given this some thought:

… and I'd like you guys to get inspired because as basic as this seems, it's so tremendously useful. Yes, we have tab sets and browsers sets, but this is easy to reach, it's collapsible, it's like an IKEA catalog for your Finder.

I can hack something like this with Path Finder sidebars, but it's not convenient at all: it's ugly, takes several mouse clicks to set it up/load the saved settings, it's not collapsible, etc.